Excitonic interaction: another photophysical process for fluorescence-controlled nucleic acid sensing.

Area of Science:

• Photophysical processes
• Biophysical chemistry
• Molecular biology

Background:

• Fluorescence-controlled nucleic acid sensing is crucial for biological research.
• Excitonic interactions in H-aggregated dyes offer novel photophysical properties.

Purpose of the Study:

• To design and characterize a novel fluorescence-labeled nucleotide for enhanced nucleic acid sensing.
• To investigate the excitonic interaction between covalently linked thiazole orange dyes.

Main Methods:

• Synthesis of a fluorescence-labeled nucleotide with two covalently linked thiazole orange dyes.
• Spectroscopic analysis (absorption) of DNA hybridization.
• Evaluation of fluorescence control based on hybridization state.

Main Results:

• The labeled nucleotide exhibited distinct absorption bands (480 nm before, 510 nm after hybridization).
• A significant excitonic interaction between the thiazole orange dyes was confirmed.
• Hybridization-dependent fluorescence intensity changes were observed in the labeled DNA.

Conclusions:

• The developed doubly thiazole orange-labeled DNA demonstrates effective fluorescence control via excitonic interaction.
• This system is applicable for multicolor RNA imaging in living cells.